The present disclosure relates to devices for use with endoscopes and other electrosurgical instruments for coagulating tissue. More particularly, the present disclosure relates to an argon-enhanced electrosurgical device for coagulating tissue which extends through a working channel of an endoscope.
Devices for arresting blood loss and coagulating tissue are well known in the art. For example, several prior art instruments employ thermic coagulation (heated probes) to arrest bleeding. However, since the probe must come into close contact with the bleeding tissue, the probe may adhere to the eschar during probe removal possibly causing repeat bleeding. Other instruments direct high frequency electric current through the tissue to stop the bleeding. Again, eschar adherence may also be a problem with these instruments. In both types of instruments, the depth of the coagulation is difficult to control.
U.S. Pat. No. 5,207,675 to Canady attempts to resolve certain of the above-noted problems with respect to the prior art by providing a tube-like coagulation instrument in which an inert gas is forced through the instrument and ionized by an electrode prior to the gas exiting the distal end of the instrument towards the bleeding tissue. U.S. Pat. No. 5,720,745 to Farin et al. discloses a coagulation instrument which extends through a working channel of an endoscope and includes an electrode for ionizing a stream of inert gas exiting the distal end of the instrument at a rate of less than about 1 liter/minute. As explained in great detail in the Farin et al. specification, the purpose of discharging the gas at a very low flow rate is to effectively cloud the tissue area and create an inert gas xe2x80x9catmospherexe2x80x9d to gently coagulate the tissue. In both of the above patents, the electrodes are not designed to come into direct contact with the tissue.
However, using these instruments to treat certain more tubular sites, e.g., the esophagus and/or colon, is often difficult, impractical and time consuming and may cause unintended collateral damage to the surrounding tissue. For example, the longitudinally oriented instruments fire the inert gas and the RF energy in an axial direction from its distal end which, in the case of tubular tissue, would be parallel to the bleeding tissue. Thus, focusing the energy transversely at the bleeding tissue may be very difficult using this instrument and may cause collateral tissue damage.
Thus, a need exists for the development of a new and effective instrument for treating certain more tubular tissue and for treating tissue at multiple bleeding sites off axis to the instrument.
The present disclosure relates to an electrosurgical instrument for coagulating tissue for use in combination with an endoscope which includes an elongated flexible tube having a proximal end and a distal end and a plurality of side-ports located therethrough between the proximal and distal ends. The tube is sufficiently dimensioned to extend through a working channel of an endoscope. An ionizable gas is supplied to the proximal end of the tube and a diffusing member directs the ionizable gas from the proximal end to each of the side-ports towards the tissue. An electrode ionizes the gas prior to the ionizable gas exiting each side-port.
In one embodiment of the present disclosure, the side ports are arranged in a radial manner about the periphery of the tube. In another embodiment, the side-ports are aligned longitudinally along the tube.
A first plenum or baffle having a plurality of apertures located therethrough can be disposed within the tube between the proximal and distal ends. Preferably, the plenum couples to a corresponding plurality of ducts to direct individual amounts of ionizable gas to each of the side-ports. Advantageously, electrodes are disposed within each of the ducts for ionizing the gas prior to the gas exiting the side-ports towards the tissue.
Further, a second plenum, surface or disc can be mounted in close abutment with and proximal to the first plenum. This second plenum includes a plurality of apertures located therethrough. Preferably, the second plenum or disc rotates from a first position in which the apertures of the second plenum and the apertures of the first plenum are aligned to permit the free flow of gas between each of the same, and at least one subsequent position in which less than all of the apertures of the second plenum are aligned with the apertures of the first plenum to permit gas to only flow between the aligned apertures to each corresponding side-port.